Epidemiological surveillance of legionellosis

Abstract

Spain is among the countries with the highest incidence rates in the European Union and has seen the same increase in trends of legionelosis. This fact has been related to the increase in the use of a more sensitive diagnostic test. However, great differences have been observed in incidence rates and outbreaks reported by the Regions which could be explained by variations in the diagnostic effort. In spite of the existence of prevention and control rules, outbreaks still have occurred and some of them involved large number of cases. The source of infection identified most frequently is hot and cold water systems due to the large number of outbreaks related to tourist accommodation sites. The second most frequently identified source is cooling towers, which produce most of the cases.